Connecting switch



April 26, 1966 R. McGlRR ETAL CONNECTING SWITCH Filed Oct. 8, 1962 NNm Ir////// r/ I g m m m a w FIG. 2

INVENTORS ROBERT MGIRR BY BENJAMIN A. GAY

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United States Patent The present invention relates to an improvedelectrical I switch and more particularly to an electrical switch whichconnects electrical contacts. The switches of the present invention areespecially suited to be actuated by an explosive charge.

Some types of projectiles and missiles require reliable, compactelectrical switches which are stable to large multidirectional forcesand which are operable while exposed to such forces, for example, whenthe projectile or missile containing the switches are in a state ofviolent tumbling or rolling.

The present invention provides an electrical switch that operates in apositive manner to make an electrical connection by connectingelectrical contacts one with another and is independent of the positionof the switch or forces acting upon the switch.

In general, the switches of the present invention comprise a slidemember moveable along a line and a pair of spaced electrical contactmembers. The spaced contact members are generally positioned parallel tothe line along which the slide member moves. At least one of 'thecontact members has a free end extending toward the slide memberarranged to contact the other contact member upon lateral pressure nearthe free end. The slide member is provided with a surface oblique to thedirection of travel of the slide member. This surface is so orientedwith the contact members that upon motion of the slide member toward andagainst one of the contact members having a free end, one contact memberis pushed into contact with the other contact member. Preferably atleast one of the electrical contact members is of a metal deformableinto apermanent set. A driving means may also be provided to drive theslide member toward the contact members with sufiicient force to deformthe deformable contact members into a position wherein there is physicalcontact between the contact members.

If desired, the contacting surface on the slide member.

tion therein.

Preferably, the terminal end of .at least one of the contact members hasa layer of solder thereon'positioned so that the action of the slidemember forcing the electrical contact members together provides asoldered electrical connection between the contact members.

Although the driving means may comprise a compressed spring released byeither a mechanical or electrically actuated release mechanism, itpreferably comprises an explosive charge fired by electrical energy. Aparticularly suitable driving means is an electrically actuated squib.

3,24 ,504 Patented Apr. 26, 1966 ice members are positioned in anenclosed space, the gas surrounding the electrical contact membersundergoes compression by the movement of the slide member and abackpressure is formed which tends to dislodge the slide member fromcontact with the electrical contact members. Therefore, .in a preferredembodiment of the invention the slide member is comprised of separablesections, with the section closest to the contact members perforationallows the backpressure to bypass the portion of the slide membercontacting the contact members and act upon a section of the slidemember having no cavity therethrough. If the solid portion of the slidemember is displaced, the displacement has no effect upon the portion incontact with the electrical contact members.

The invention will be better understood from the following descriptionwhen considered in connection with the accompanying drawings.

FIGURE 1 is a longitudinal cross-sectional view of a switch in accordwith the present invention.

FIGURE 2 is a longitudinal cross-sectional view of a modification of theswitch shown in FIGURE 1 wherein the piston member comprises twosections.

In each of the views like components bear like numbers and for the mostpart, the switch in FIGURE 1 and the modification in FIGURE 2 may bediscussed together.

A generally cylindrical metallic outer shell member 11 is sealed on oneend by a plug of non-conducting material 13 and on the other end by asecond plug of nonconducting material 15. The plug members may suitablybe fabricated of such non-conducting material, as plastic, asphalt,rubber or glass. Preferably the plug members are fabricated of a ceramicmaterial. A pair of spaced electrical contact members, 17 and 17' entershell 11 through plug 13 and terminate within the shell. The electricalcontact members 17 and 17' preferably are of a metal deformable into apermanent set, for example,

copper or brass. The free ends 19'and 19' of contacts 17 and 17' arecoated with a thin layer of a solder 21, of metal or metallic alloy suchas gold, lead, tin, silver amalgam, lead-tin or indium alloys. A slidemember 23 having a cavity 25 is positioned in shell 11 in spacedrelation to electrical contact members 17 and 17'. Cavity 25 is alignedwith contact members 17 and 17. Cavity 25 is of sufiicient size tofreely receive contact members 17 and 17'. Wall 27 of cavity 25 tapersto a narrowed opening 29. Narrowed opening 29 is of a size such thatfree ends 19 and 19' are tightly squeezed together upon insertiontherein. Slide member 23 is preferably fabricated of a non-conductingmaterial, for example, resin, hard rubber, compacted fiber board, orceramic materials.

In FIGURE 2, a modification of the piston arrangement is shown whereinthe piston has a first piston section 31 and a second piston section 32.The first piston section 31 is similar to piston member 23 shown inFIGURE 1 except cavity 25 extends completely therethrough to provide ameans of equalizing pressure on either side of piston section 31. Thesecond piston section 32 has no perforation therein and represents asolid obstruction across shell 11. Although the second or solid slidemember section 32 is preferably fabricated of a non-conducting resin, itmay be suitably fabricated of metal or other conductive materialsuitable to prevent the communication from one end of shell 11 to theother.

The'switches shown in the drawings both utilize a gas-forming explosivecharge 33, suitably composed of lead mononitroresorcinate, positioned inproximity to the slide member. A firing means comprising leg wires 35and 35' enters shell 11 through plug 15 and is electrically connected toa high resistance bridge wire 37 embedded in charge 33.

In operation, the gas-forming explosive charge is fired by applyingsufiicient electrical energy to the bridge wire 37 via leg wires 35 and35 to fire charge 33. The gases from charge 33 forceably move the slidemember toward contact members 17 and 17. The tapered wall surface 27 ofthe slide member causes contact members 17 and 17' to be bent inward andinto physical contact by lateral pressure on said contact members. Thefree ends 19 and 19' of the electrical contact members are coated with athin layer of solder 21 and when forceably joined form a solderedconnection. The free ends 19 and 19' of electrical contact members maybe angularly cut to present a meeting face with tapered wall 27 of theslide member.

Although after firing the connection of electrical contact members 17and 17' is completed, it is often desirable to protect the connection bymaintaining wall 27 of the slide member in tight contact with theconnected electrical contact members. The modification in FIGURE 2 showsa means of providing such contact. The gas in area 39 around electricalcontact members 17 and 17' is compressed by movement of the slide membertoward contact members 17 and 17'. This movement forms a backpressure inarea 39 tending to force wall 27 of the slide member out of contact withthe connected contact members. The modification shown in FIGURE 2prevents this action by extending cavity 25 completely through the firstsection of slide member 31 to form a gas passage. The backpressurethereby bypasses the first section of slide member 31 by passing throughextended cavity 25 and acts to force the second section of the slidemember 32 toward plug 15 which does not affect the contact between wall27 and connected electrical contact members 17 and 17.

It is obvious that modifications and alterations of the presentinvention will occur to one skilled in the art, and it is understoodthat changes can be made within the scope of the appended claims.

What is claimed is:

1. A switch for making an electrical connection comprising a sealedouter shell containing,

4 a pair of spaced electrical contact members having free ends extendinggenerally in the same direction and made of a metal deformable into apermanent set,

a slide member having a contacting surface and moveable in said shelltoward said free ends in a direction generally opposite to that in whichsaid contact members extend,

said contacting surface providing a means so oriented with respect tosaid electrical contact members that on movement of said slide membertoward and against said free ends, said free ends are deformed bylateral pressure into contact with one another, and

a squib means in said casing to drive said slide member toward saidcontact members with sufficient force to deform said deformable metalinto a position wherein there is physical contact between said contactmembers,

said slide member comprising separate parts separately slidable in saidshell, one adjacent to the squib means, being an imperforate pistonmember and another, comprising the said contacting surface, providing agas passage between said piston and the locus of said electricalcontacts.

2. A switch in accordance with claim 1 in which said contacting surfaceis obliquely inclined toward said electrical contact members.

3. A switch in accordance with claim 2 in which said surface comprises.a side wall of a cavity in said slide member, the space between oppositesurfaces of said cavity narrowing within said slide member from a sizesuflicient freely to admit said spaced contact members to a size suchthat said free ends of such contact members are tightly squeezedtogether upon insertion therein.

4. A switch in accordance with claim 3 in which at least one free end ofsaid pair of contact members is provided with a layer of solder.

References Cited by the Examiner UNITED STATES PATENTS 2,141,098 12/1938Wahlstrom 339-276 2,558,188 6/1951 McWilliams 2O0l53 2,816,196 12/1957Daudelin 20()-142 2,931,874 4/1960 Leaman 200-82 FOREIGN PATENTS 921,4631/1947 France. 826,891 1/ 1960 Great Britain.

BERNARD A. GILHEANY, Primary Examiner.

1. A SWITCH FOR MAKING AN ELECTRICAL CONNECTION COMPRISING A SEALEDOUTER SHELL CONTAINING, A PAIR OF SPACED ELECTRICAL CONTACT MEMBERSHAVING FREE ENDS EXTENDING GENERALLY IN THE SAME DIRECTION AND MADE OF AMETAL DEFORMABLE INTO A PERMANENT SET, A SLIDE MEMBER HAVING ACONTACTING SURFACE AND MOVEABLE IN SAID SHELL TOWARD SAID FREE ENDS IN ADIRECTION GENERALLY OPPOSITE TO THAT IN WHICH SAID CONTACT MEMBERSEXTEND, SAID CONTACTING SURFACE PROVIDING A MEANS SO ORIENTED WITHRESPECT TO SAID ELECTRICAL CONTACT MEMBERS THAT ON MOVEMENT OF SAIDSLIDE MEMBER TOWARD AND AGAINST SAID FREE ENDS, SAID FREE ENDS AREDEFORMED BY LATERAL PRESSURE INTO CONTACT WITH ONE ANOTHER, AND A SQUIBMEANS IN SAID CASING TO DRIVE SAID SLIDE MEMBER TOWARD SAID CONTACTMEMBERS WITH SUFFICIENT FORCE TO DEFORM SAID DEFORMABLE METAL INTO APOSITION WHEREIN THERE IS PHYSICAL CONTACT BETWEEN SAID CONTACT MEMBERS,SAID SLIDE MEMBER COMPRISING SEPARATE PARTS SEPARATELY SLIDABLE IN SAIDSHELL, ONE ADJACENT TO THE SQUIB MEANS, BEING AN IMPERFORATE PISTONMEMBER AND ANOTHER, COMPRISING THE SAID CONTACTING SURFACE, PROVIDING AGAS PASSAGE BETWEEN SAID PISTON AND THE LOCUS OF SAID ELECTRICALCONTACTS.